SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62a1980c85e381fd3fe0eb146bedf0ffea51b2ac8f3e458baba693d1f7a487ff' 
  AND token = 'e1Vo3TjsSMyLdXoDCZohBT+GZ0AfZ1WFzmonajQ/OKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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