SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33d9625156971ba40612f598af55ea2a0789acfe9ccf7519a264bce5096d2ae7' 
  AND token = 'GtPn2P1lP8PdgeWhKl1CRJfYlzg8TOeI4BYbH2NYvug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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