SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c73fca0134d17032b80f1f66f360232c16a2aee598a16eb4533289ac05495d0' 
  AND token = 'yOpLw0ATJNljTtDvVT+qim7qOp3hCwTKB81DCPp0Q1k=' 
  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"
    }
  }
}