SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '490ede82c16aa82323d2b0e1b2a0583979dbe22a4eb1d47d9bde32ba777bf176' 
  AND token = 'ls5H6jruHyb8o+SYDOuZjmV3hGglOw0eQBRuJxmF8qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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