SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '025651b500e087ad86d9f3c036bc9b75f682018efccf8abc3e3bbaa5c324186f' 
  AND token = 'mdkFzvGbtErKu+fQC4pkzT74z1iWArV4BLqvL9BN6KE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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