SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '328b095f9a8ea8b09ffccedab83496e18ee6cd55f608b50bd18c10dc029130e9' 
  AND token = 'nlE70unNagrDnSEF48nmRGoLzzIVc/PjGBAMoH5CeI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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