SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a99b3799337136dc7333904fda36d48b37292b560db5109feacb4ab1918da15f' 
  AND token = 'NPvSVNQyRo/d2h+a/QzGkZaFBIuXvlpDLbxVjQLM/cE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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