SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b69fde135fa11ceac9aa0bacc146f5a50601fefe991283631bca185e79ac0530' 
  AND token = 'tYN2JdPzPmL1FvIOYgGqhc0mHWvZamv/VxLOvRW/o/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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