SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49364b94db8d8408242f4e41bfedbc8408624ade6c9baaa2cf2265f23483a607' 
  AND token = '3BTxS8T/Jqko2cFjnjIKWogYzotWdNu0qzqhWWwaasM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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