SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bf92296e4bb4086298082f434a74ee70f624c1ec3263e61b6fb56e528294c8f' 
  AND token = 'NOkaEg4Y1LG0dkyRswDv0i2nnGT3vJRxLrul4XJ3AJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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