SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '03e0f875347c88caa6dadd2b9cbcfca26c277a6c6b888995d6adec092c04cf9b' 
  AND token = '4Yk0DHCN9NFYUX9uUt0layNpaAOwSRyJjtdee0+dscw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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