SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d2f5f836591cb46fb525e7c7ff7197c2b8cef33caabed60499e2e483f2ffae1' 
  AND token = 'ldgJVEX1w2KBcOWhs8lgT5l9V7QgBO8ujF2YzXc/91g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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