SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f7e1d28b25825beccce56547879922692ec51dc2628987cc1dfe364dd293fea' 
  AND token = 't+vxYKK3ky0xIuYgbzwnWU82FPAA/YjjOawup7KFMqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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