SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9863f7f15180d4d478c1bcf44aadbd6ae421b16a20aedaa55934b0720242d031' 
  AND token = '8BRSDpqQsM/TIYXdPAgYpcN0OscZ9xjtDggriccw/SY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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