SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dc4cadb39144254809e5e51e7cece3a8b86b2f3ed27b57dcc03c2f618751332' 
  AND token = 'hfIpjvRjtAdsU9x8gWKQXsu85ieWP+iWzJNJZ7uzLhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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