SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33c9ef83350b539323d749e618f033e2d7b3e0df6145865111cd918586222f23' 
  AND token = 'FPZ32ubCE/Q17K5hDouqpgB+LVdm4YJARWFj1XoJnI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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