SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e5d470667b313135b2082117e01469d58ebf6e5a5076de61f49c041a66e86576' 
  AND token = 'mTLL6ZvMSm4bQhYhBsnZ4Zfrt9purG6ctb8ayLhYOQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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