SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ef56c2ccc882e9ac948d3eaee6917905eaebebfa2bce5850c68803b618828f5' 
  AND token = 'QP0K/nwdHSjWX0SQz9Ipjw2cfE5QMHltI21qxaMOjOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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