SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aca533e4f5c90705c21a5aef869bd9603b4d93cedf35311156c8af4c642096f6' 
  AND token = 'EgwMjh5cqGKpD8NLPKNBRqE1qAO9LfflTYSnu/3Ix+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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