SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0af38e1954665f649862e940cf8f147d53af267fccaae3ccdbba43086e886bc' 
  AND token = 'Crzb5hHHzrSaNPBMyZ53tvOWN1+Vo9NWCp0PfjPGqOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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