SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8192b874a111ed13df284849abed57b1cd66491dfeeacae59e18468d10b70ef1' 
  AND token = 'Dtl3675TGvDGg4CgaYgWkhiUJiL1gV4NOL10KRd/8Us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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