SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2473dbf0fdf4bda263af099cbc433c07bb46a95397c3baa5f3f0fbd2877ab21c' 
  AND token = 'HgaTMSO9kkmsMXcHLy8d9M0b1+VOtaTunEogMLsXCi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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