SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bc753ca25536316be8c06c217c3ebdb29718868de990b1ca3922b9a99f80d31' 
  AND token = 'e+4qJBApb/TrXDFeHIVoBe/UodlYAJ+MhKZ/Prf+jEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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