SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1786fa686765c729c0b6485fb40b27de7c3f3adf8c821dd3b434029c77e3b20a' 
  AND token = 'N1rAn6jiKfBVjROhz4WvtexRKDB+UgGzNwBrouvi7oo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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