SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8cda243309ab4131b4a962a54c38f3039671a09c148273c0616dcb2afc54cef2' 
  AND token = 'dAFAKqz76VoQPdFxsRFAKUn0uQ1XgNei/dv3DhLYQwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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