SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0f9f5f321dcf4dee18a20f8fdc1a7e6bf2444bf9ded2918bbdd64c8715ad50f' 
  AND token = 'pqxEMllVqTeizak2krrOWyHMsjbEKaqgnaiZant5dns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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