SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59cc32b518347816a6a906f6984e5d31e0bbc04970dd58c787bf5a3e7e7f3269' 
  AND token = '9SUDUwuUEja2RPqO14d/vlfmYgGkSlRYnLO1894CF4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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