SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4815267afa0daa0371bf10357a6dc92a76074e8ba167de579f91366e32c7a832' 
  AND token = 'ojo+KWvXGKKh7hXzd7/msPa4cVAfYgTtlLHzArZ9Wpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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