SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b1f70699bf4aff0f5fc34fa6fe2d91aadcaa3521e37b055799bcdf0619343c5' 
  AND token = 'XMSlI5WWHRW7eDMdBe50EYf5aqyc+V4Zz/czmcCOVzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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