SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3416a5928b68208df3efacf50bfed8e479ec7fc0e48b3cc89f964da3e68b894d' 
  AND token = 'hDm6pvq4sK+bc/7P5q/pLWCAgwHLthTPGzBLA9JfQIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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