SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b64bf177ab5fb34001630d1ac940dc1c86e556b7f92b4666cd69b45b27c684c5' 
  AND token = 'DFam66OiHDGZPFUxZaM1w14jVfMbKgy7NFQWPo1fqlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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