SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f216f22ba97d1db3d1f4f1018560d81320ff04b461f1a370a1a0635184c6b70d' 
  AND token = '0/Uv9QBrPxI4T9fJXB3Jau9X+D2WWkF2CgBuSIZmh2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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