SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b31e5a01c177bad78ca553b42d01704d3c95f0a6b0f47ce823cfc984102811f' 
  AND token = 'edOnCMB76sbxSPw5fKkPAYdHPwSkjx/KcU2ysN2TeYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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