SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54b92961aebc37672228b57e42802d672777cc1f34748d5e602894dc63e04a46' 
  AND token = 'zX4n4+aS4/tx17iWxXYvBwwSTbM1+9fYs0QEup9yKLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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