SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c96c2139a0853405755aa85b5ff69659147b0b97cfaf6b0d45519121497e7d2' 
  AND token = 'SiD/aRUWe66kYY9LGRiqGF1CpjV2Q4bYpqBw/qHF8dM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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