SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed0ac0931c62402ee2bbcff67cce3441fe56f9b2b40830461bf49c766a4098ea' 
  AND token = 'i99cJtcnkxFzgW1q+vKTS0n+ZPvnvf1zvd+g5vIyeoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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