SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a07abe25796daaeecc8c19647950204cf70d15bc1adc8a9f7bf96a896a8a7b36' 
  AND token = 'rk6W9O7CTNURZrIRb/dfOsHOkOvqRI59Ly+dHEx+TRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}