SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ef3f0773e6c80817a9e5866c8f24f5ecb37789d3ea8bc1e1ae07fdd64d8ae06' 
  AND token = 'UAe86rBMW0xdA1NgEpEe+jYcVci6ZwVxcPkdCOqXYak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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