SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edd0fc99158ab99d5face4f66349319ee2343b38a89b253f865d33697aba9ea9' 
  AND token = 'NeyKnWcjb06SW+OS9IsgxYzPOW8HMbUZ8cBg6tdxYEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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