SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbb617d695dc8784fce282330e2469949f52b885ad2ef3c51cf041109b0ac23d' 
  AND token = 'w+iHvh6mOtjBXHB0aUmA1sZeh9tqh9FuCD5BsW+6gs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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