SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e5ece883c99b81ab6f17cd047c993ed7c581ab65c49fdcec86ae6edbccda007' 
  AND token = 'arSCu7Ldk7IdmO8XAaMJ/Y0iAzwCYmcCYIGo/NA5Rss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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