Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7eb75a1a146cb8c36bd37775602061b3fe9d8c45ca13fcf66a3dc93bedefc51' 
  AND token = 'pMC75ksCqwJ7c93PgSZT2sRJeoY5QhExQJsmfknjq8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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