SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53f81d71d0af02773fc709a72f631d0cfa0e7df4c17fcb8eea77ab600708a9fd' 
  AND token = 'CGo40G9z/guLz2GU7iQcdNdG1/Pbp2LmTHZ7AfhqSf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}