SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2acf697f645a2cf6ce72bef13121e8272facf12f9223117581628828abf4c8cb' 
  AND token = 'cLgH3xGUwnouqXRUELDEKSNJQiJdDZ0pSHqtATR1jtM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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