SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9aebe68245f0b2b4a47928c5fa47f501904685423c7ef165bebddcd15074bfe' 
  AND token = 'gTZDW+Et7aedLyYx+ycJYyHlgJPRGJiqr9EoxN6B+UY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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