SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bc902abaf813235bcfcabce6bcc35d7a081ce8b0b41731181c5585976a3aa32' 
  AND token = 'IGHrAItHBYMbPtM3pDIi9/LLrH30hcKnqAQ2mNhEO/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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