SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bfd1cda439ff7ec819b59e9edccfc13dc9d32bcf60fff589dec1788d67ca814' 
  AND token = 'P4RkQxiH2k/Lvf4TDCkrzILTXSWOwBioD0Jwd4fmXNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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