SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45c9803117287c525523ffcb79841ce5d9b9bdf96a14717f06fa7942cef0e5fd' 
  AND token = 'CGTj5oLMG0KJKFYxg7P8Tm28dCyOO4LUKaGZ+/G5EBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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