SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd3179e689b57626a2c8082750ba8be6a36950d3e39ff276f4592f0c4e301afb' 
  AND token = 'pYp+fKNbjkthTSZpuN4nyZpwDAFFtbUTRTGbuvM4LRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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