SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b5717a67eb89aed7eba587de1a464d2aa52e825af1c7d498a99d843398289ea' 
  AND token = 'ZQwA9udYuyv7LmtOM54jXV9A+jfjlEl2eZs/gI+ngpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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