SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b37462af0157e4701f499260e42b351a00651bab9c17cdbfe25e048feb23c02a' 
  AND token = 'InmuF/QlNHVwhRPkykoF2DvsnJwcpPSJrbpG515k0as=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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