SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58984e1101f355c0db860a0506e4dcb9814a8ce15724e062515f0ffa787c23af' 
  AND token = '4B/Nm7ajjS9LH6yO7sGQeeYAYorblN1T644BfvTTOvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}