SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '67d2934de5739bc5d6add3164dc040e5557f53bf453d5f5291271df54263d875' 
  AND token = 'tL33rkjMZRYxZitBVwngFj4PgqS50kvwByYTtIz5Cbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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