SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a0323066cee19e802bfb35b16f3afba8f9ba18bdd7e43b1ed3e9322fe0f4629' 
  AND token = 'viYOtuxDsh7/r8sP73c/DZxKRnGAaUyR4vUu+cA8vP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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