SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5c9a004c75d85530cdeeb6e601146e6e8b0430debc1d4b4604cb21560c69d4c0' 
  AND token = '4b5vOb0Xc779Hzxz6bdFMXnUd4ceI/tSOerKcfhOnOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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