SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b74531077a8caf228db588894dcb75a7ebdc0f3aaef311d5323429370990c5bd' 
  AND token = 'OL0Vs8ESmG6fOD8lWfzI9UnoNLl56E2BRNU6lgLYjaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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