SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8e67c3eb514e55f209c849895268a6203c5fc400ac42bce525e3f218a6203f31' 
  AND token = 'fHkKqU+TKOQ1Q6GcIg/NYQ1oQdVJheUEhZnkpxU8PRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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