SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dde443a0ba41a32ad816fe9569add1a2f9c2999f38380b1bfc11742d0b4f5c1' 
  AND token = 'IHtGjWq5VtyvwLrZro/XR5G0PhQVxMAYJtQ/aDqIl+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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