SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '501a4ac6f574a1ca714c05fef1e6702b33132f4757619357188e009ce247e091' 
  AND token = 'PWXsj4SsKvEc1ItM8NbWQkX9b6qlprnkR7krcW8kIZs=' 
  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"
    }
  }
}