SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '636863fce590664d6f5285f0863a8f0f5c20fd19814ef965c804e1da5841e9c9' 
  AND token = '8XUp8PdyKBEkz7FqLbU3jxhfaWW+4ARTRCdmgll3s+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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