SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dacf0a23f79d0361d8bb01f0be840b70e027427c4e2fa5c1659e99cb72ee459' 
  AND token = 'FZLGVL0gl+FY/9XcdpjY0tm8+fBn1dXb+TzMsTKWM3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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