SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '889d16e9430915def16cd1b1aa6d053691ee48598dc4f00836d5811310315557' 
  AND token = 'O7cpVTJCWaqyAi1ABXTmirpC+YeV0YpSooz3cKqs3Sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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