SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28676f917d2340654649fea2b95f0a0b81b9c1129f8b8b6bbe2673f53786088a' 
  AND token = 'BPvwYJs619Hp1VaEkh/bZgBzMxEI7ZQjddshLkN1qSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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