SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c22d51d88723772e53f73b86c0b7a1fc0f123fdd75fe6088a376b069c34cd5a2' 
  AND token = 'yUSUBDwBwitFiN57kjf10pGjn5FGmbvXUsF9vtt/Qoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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