SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a9a3ec9c47cd05337575c450041c8afd82f1e3be6743f2f0d8d15314eac8bccb' 
  AND token = 'M2OiOI3JrfBVRcOJ8fiU6GccP2rjx0xW21n9cKjSqvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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