SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '885f1201b24da387c0a48a76d864e887868a59fb33489dd75611ea0d55261890' 
  AND token = '+XjdutLuCQ+LYWjSG3xkxM1sfY9w2QobvDNSyht5oXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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