SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66ac2d887a5c29c42384dd628870eb8f463dae21d8b71b00c927a49a6d04f33a' 
  AND token = 'CAyR1vPckKddTZSM5lPIMRCnpf2WWweQ2MiPcU4XMX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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