SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26e870321d4e244059346fc6ed11f8b8092c001dfe308a647a22dcae2ffb3f42' 
  AND token = 'Fltw9RI3XcKVd6DIDjyiKFP/fc5tEWsWSjuRJygtVOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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