SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87a22256de50fa7e092e9542d5e34c518021b77d6719c830ce9fdd4ea946c2e3' 
  AND token = 'bwXa6uU+zTI5p6NsK7peW96/PRAHt8sIl3NF5DK4MpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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