SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5d63c30e53678891f722a631872a9bee737df6f6629795f8acb05dee08b0587' 
  AND token = 'TjyncprTCXYxPFKEYvIYkXZhnScTprSTWYLEWzcu/78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}