SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8acaf7f602bb23fa23852755836aa8f1eb28083ef684c700a1b44ba6734887b' 
  AND token = 'L2gpVjHDDFaqTEAx4/NLZah8SFV/0gUaTl7n39tSEnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}