SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dc4dc40fc58b3b0aff23fc6f4558db3db5188dfc799b2cf5082deb7c65c801f' 
  AND token = 'Wcr5fjTN5YquPAg9lmZANVywkKvjYnR3/UICHdKjhhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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