SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c40ae7233613a1e5e409e663ff1f225e5721328b4981c51e2bf90eebc2885369' 
  AND token = 'yvr6mFI/4VTAuBzO8M9mlSYwIHEtVLKrY9wqC+0KVZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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