SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47b45b125a2d3a85786af08af7c42db1132536eeadb3402d8ddc72e2da65c331' 
  AND token = 'Byt7ny2ZDNP9wRW03n8CyndMhSqxPQ7be82RpRAQQC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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