SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87302b1cafb6f65b9f77ff76be3ae4bdeb782fd70793af56c51269646709bc92' 
  AND token = 'jlopENtKJN8RCUjUqaLXjMBFuxaNabn0cSJ/R1m+Rq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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