SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30e5f40be35cbac6ad0376d6efa68c70285a145bdb04342a67941ff864ae163f' 
  AND token = 'rlhBG5kqsHvL55/jyQFLzpSdcPBBNpQ4FZ1VOahkMpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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