SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '145c58818f244a2018acdae82ad20ecae0d6bd5e07f4429bc00a51bd338b8750' 
  AND token = 'iD1EklmN3QkcZvFteYtNU1HDmb7xZsAWL2FqLtA0tdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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