SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '45bc0948b62cd7bea0d250f956fe26ae6be5f76b4d1eaff6c226561ff3b918e6' 
  AND token = '6c/jDYM/vQIKwluPve5kZkAiRJ+hni4jalwYFass6CQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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