SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd42971a687afd4d05a8cea43f7072b48d599b5249f06c386cf027ef9985216d' 
  AND token = 'ov1n7yYGgOQu6mDBYob8aVzocF6RP/O02YFKqNSZb4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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