SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45d3a19327d8e219d9f8867bb2285c85e53c5de15fb6f8fc53338fa4e0e419dc' 
  AND token = 'k0PpB2p7ZKNNZ40WgoU13uMNsjdABsNGm93SAFDWzNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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