SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e649bee816010423530938fe73a335fb0850a8fa11bb2d45655491168e411e50' 
  AND token = 'p34Iid2Ba1bRvQGVUwj7Uw60R6a6ql0LATFCy+248Iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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