SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e96886992d63d461bcfddf84b643766aebbe7db1541dc09c900571a3345059fe' 
  AND token = 'DfPblt7f56eI+fUEmtVdVsuGQ3vli464TPXxl2JLOmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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