SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c981557e16b5a1b6d7056d01f425682b7847c934302d0ef6df4251750f6786c' 
  AND token = 'p2i+pyXPDgYS7ZYldoOLqGSTBYm6KPQ/7vheqQnC4ZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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