SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9ec22a936d31bf89b9c155a36065e0d098afa8f35d662b865992a8391297cda7' 
  AND token = 'koLJIauFuE/94VsSLjkwvglMw4FIK7/5x0CKjD3DjSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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